1. Field
The present invention relates to an inflatable cushion and, in particular, a self-inflatable cushion particularly for chiropractic or orthopaedic use.
The present invention also relates to a mattress including the abovementioned inflatable cushion.
The present invention further relates to an air valve assembly for use in the abovementioned inflatable cushion.
2. Related Art
Cushions, including pillows, are extensively used in domestic, recreational and therapeutic applications. The demand for comfortable cushions is very great and this demand is increasing as the standard of living continues to rise, particularly in Western societies.
Cushions also have many uses in the healthcare fields, particularly in relation to persons who have chiropractic, orthopaedic or similar complaints.
As is well understood, typical cushions incorporate an external coating (or skin) which encloses a soft inner core. This inner core is generally formed of feathers, soft foam or other similar materials.
Inflatable cushions have also been developed. Such cushions generally consist of an inflatable bladder, an internal chamber, and a sealable air valve for enabling air to enter (and exit from) the chamber. In these products, air is typically blown or pumped into the chamber, via the air valve, by the user. Such products have become popular in camping applications because of their light weight, ability to be deflated into a small volume, and their ease of use.
Such products also have been used in chiropractic and orthopaedic fields. For instance, U.S. Pat. No. 6,047,025, in the name of Adnan Khazaal, discloses an ‘orthopaedic pillow’ which incorporates a hollow inflatable bladder which is able to be inflated by means of a hand pump.
Similarly, U.S. Pat. No. 6,327,725, describes a ‘pillow with adjustable neck support’ which includes a foam pillow having ‘an inflatable airtight chamber . . . for providing adjustable support to the user's neck’. The hollow chamber is adapted to be inflated by a manual hand pump.
Another U.S. Pat. No. 4,829,614, discloses a pillow having an adjustable neck support which includes a number of separately inflatable hollow chambers within the pillow.
A further U.S. Pat. No. 6,397,415, discloses an ‘orthopaedic pillow’ having an inflatable hollow air chamber and a separate water chamber.
A benefit of inflatable cushions is that they can, generally, be inflated to any desired level according to the requirements or desires of a user. For instance, if a firmer cushion is desired, it can be inflated up to (or near) its full capacity. If, however, a softer cushion is desired, it may only need to be partially inflated. This can be particularly advantageous in the fields of chiropracty and orthopaedics where it is beneficial to be able to select and alter the degree of firmness/softness of a cushion for use with a patient.
In more recent times, self-inflatable products (such as mattresses and cushions) have been developed. These products typically consist of an inflatable bladder, an internal chamber with a compressible foam substance within the chamber, and an air valve. When not in use, air is expelled from the product and the foam within the internal chamber is compressed and the air valve is sealed shut. When the product is to be used (e.g. as a mattress), the air valve is opened, enabling air to enter into the chamber. This then enables the foam substance to expand to its natural expanded state. As the foam expands, this causes further air to enter into the internal chamber, thereby causing the product to self inflate. Such a product is disclosed in U.S. Pat. No. 6,016,582 in the name of Lynn D. Larson.
A problem associated with existing inflatable cushions (including pillows) is that they tend to exhibit a bouncy feel when in use. For instance, when fully inflated, the cushion is hard and uncomfortable to lie on. When under-inflated, the cushion tends to provide inadequate support. Somewhere in-between the fully inflated and the under-inflated states, there may be a state which is reasonably comfortable for a user. However, it is time-consuming and awkward for a user to try and identify this state as it involves manually opening the valve (typically by rotating a rotatable cap), expelling air or blowing air in, re-trying the cushion (for comfort) and if not comfortable, repeating the process (perhaps several times).
Also, inflatable cushions tend not to provide any resistance—and therefore no real support—against any sideways or rotational movement of the head (or other part of the body). Accordingly, such inflatable cushions can be rather uncomfortable. Also, and for similar reasons, such inflatable cushions may be disadvantageous to persons suffering orthopaedic or chiropractic problems.
In the fields of chiropractic and orthopaedic treatments, it is desirable to have cushions which do provide adequate support to a user's head (or other body part). It is further desirable to have a cushion which is adapted to vary in firmness depending on the size of the user, the user's particular condition, or the degree of firmness of the cushion which is desired by the user. Alternatively, quite a wide range of cushions, of different sizes and/or differing firmness, need to be produced to satisfy the various needs of different users or the same user at different times. None of the products described above satisfy these criteria.